PRADAXA DANGEROUS WITH HEART VALVE REPLACEMENT

December 21, 2012

Here is an important message for people with mechanical heart valves who may be taking the blood thinner, or anticoagulant, dabigatran (Pradaxa).

On December 19, 2012, the Food and Drug Administration (FDA) issued a safety alert warning that Pradaxa should not be used to prevent stroke or blood clots in patients with mechanical heart valves. The warning is based on the results of a clinical trial in Europe showing that those with mechanical heart valves who used Pradaxa were more likely to experience strokes, heart attacks and blood clots than those using the anticoagulant warfarin (Coumadin). There also was more bleeding after valve surgery in the Pradaxa users than in the warfarin users.

People with mechanical heart valves taking Pradaxa should carefully transition to a different blood thinner, such as warfarin, under the guidance of a health care professional. You should never stop taking blood thinner medications without guidance from a physician, because stopping an anticoagulant suddenly can increase the risk of blood clots and stroke.

Pradaxa is currently approved to reduce the risk of stroke and blood clots in patients with a specific kind of atrial fibrillation (irregular heartbeat) known as “non-valvular atrial fibrillation.” Non-valvular atrial fibrillation occurs when patients have an irregular heartbeat not clearly linked to heart valve problems, including having had a heart valve replacement or other type of valve-repair surgery.

Pradaxa is not FDA-approved for patients with valvular atrial fibrillation, or irregular heartbeat caused by heart valve problems. Nevertheless, it is quite likely that some patients with mechanical heart valves are taking the drug. The FDA warning directs these patients to immediately contact their physicians so they can transition to a different blood thinner medication. The FDA also advises patients with another type of heart valve replacement, bioprosthetic valves, to talk to their doctors about different blood-thinning options, including warfarin, which is commonly available as a generic drug.

In addition to Pradaxa and warfarin, the other drug approved to treat patients with nonvalvular atrial fibrillation is rivaroxaban (Xarelto). Since Pradaxa and Xarelto were each approved within the last seven years, Public Citizen recommends against using them under our “Seven Year Rule” because they have no unique benefits, significant safety risks are still poorly understood, and warfarin, the other available alternative, has been studied for a longer time.

The FDA previously issued a safety communication for Pradaxa in December 2011, based on reports of serious and sometimes fatal bleeding events with use of the drug. The bleeding risk with Pradaxa is similar to that with warfarin. However, doctors have ways to reverse dangerous bleeding related to warfarin, but not to Pradaxa . Similar problems are present with Xarelto, which also has bleeding risks that cannot be easily reversed.